@article{Iliev_Georgiev_Kotov_Dimitrova_Malinova_Rashev_Tsankov_Karabinov_Landzhov_2017, title={Immunohistochemical Study of Matrix Metalloproteinase-9 in Medial Collateral Ligament Epiligament in Rat Knee after Grade III Injury}, volume={3}, url={https://www.aijournals.com/index.php/aanat/article/view/89}, DOI={10.21276/aanat.2017.3.1.6}, abstractNote={<p><strong>Background</strong>: In the present study, we conduct an immunohistochemical analysis to evaluate the expression of matrix metalloproteinase-9 (MMP-9) in the epiligament (EL) after grade III injury of the medial collateral ligament (MCL) in an experimental model of a rat knee. <strong>Methods</strong>: Twelve 8-month old male Wistar rats were used in this study. Three animals were used as controls, while the remaining nine underwent grade III injury of the MCL. The MMP-9 immunoreactivity was evaluated on the 8th, 16th and 30th day after injury. <strong>Results</strong>: We observed an intensive expression of the enzyme in all periods after injury in contrast with the control group. We also discovered that the main source of matrix metalloproteinase-9 was localized in the epiligament tissue. Immunoreactivity was highest and homogeneously distributed on the 8th day and gradually diminished, concentrating on the EL-ligament border and the perivascular zones on the 30th day. <strong>Conclusion</strong>: We present the first immunohistochemical study of the expression and distribution of the enzyme MMP-9 in the EL of the MCL and track the changes in enzyme activity on the 8th, 16th and 30th day after damage.</p&gt;}, number={1}, journal={Academia Anatomica International}, author={Iliev, Alexandar and Georgiev, Georgi P. and Kotov, Georgi and Dimitrova, Iva N. and Malinova, Lina and Rashev, Pavel and Tsankov, Lubomir and Karabinov, Vesselin and Landzhov, Boycho}, year={2017}, month={Jun.}, pages={20-25} }